There is an increasing trend in motor vehicle body design, and in particular private passenger car body design, to assemble the vehicle supporting structure from light metal elements. An example of one such system is known from European Patent Document EP 0 146 716 B1 which discloses a vehicle body assembled from a plurality of extruded light metal hollow sections joined together by cast light metal node elements.
A disadvantage which such a light-metal bodywork design however is that in view of the lower yield strength of the light metal material as compared with heavy subassemblies, such as for example conventionally used sheet metal stampings, doors or the like, cannot be directly fastened to a light metal frame member without additional and often expensive reinforcement.
It has therefore already been proposed to provide on such light metal castings additional metal holding parts (holders) which serve to hold the heavy subassemblies. However, in order to mount these holders on the castings, it is necessary to machine the castings after they are formed. Thus, a relatively considerable expenditure of time is required for finishing the connection between the holding part and the casting. This additional time increases the cost of assembling the motor vehicle.
Accordingly, there is a definite need in the art for a light metal casting for use in mounting heavy vehicle subassemblies to a light-metal frame component which does not require additional machining after its formation in order to receive a metal holder.